U.S. Ser. No. 10/459,526 to which reference is made for the sake of completeness, discloses a double-cylinder circular hosiery knitting machine equipped with a device which, at the end of the formation of the hosiery item, extracts from the machine such hosiery item, which is turned inside out and is aspirated into the upper needle cylinder, and automatically inserts it, with the portion of its toe that must be closed, into the conveyor of a sewing machine.
The device that transfers the hosiery item from the double-cylinder circular machine to the conveyor of the sewing machine comprises two grippers, which can engage two diametrically opposite regions of the opening of the toe of the hosiery item to be closed by sewing, so as to hold the hosiery item so that it hangs at its toe to be sewn. The two grippers can be moved apart on command, after engaging the toe of the hosiery item, so as to flatten and move closer the two flaps of the open toe that must be joined by sewing in order to close the toe of the hosiery item.
The two grippers insert the portion of the hosiery item that lies proximate to the opening of the toe to be closed into the conveyor of a sewing machine, which is constituted by two laminas that are arranged side by side on a substantially horizontal plane, so as to form between them a passage for the portion of such hosiery item.
The region of the hosiery item that ends at the toe to be closed is generally produced by providing an additional portion with respect to the actual hosiery item, which is used during the placement of the hosiery item on the sewing machine and is designed to be removed during sewing. This additional portion is composed, starting from the body of the hosiery item, of a few rows of knitting formed with an elastic thread that has a reduced diameter and of a final border that is thicker than said rows. The hosiery item is gripped by the grippers at the thicker border and is dragged by the grippers, which move above the laminas of the conveyor of the sewing machine, so that the insertion of the toe of the hosiery item in the passage formed between the laminas occurs so that the thicker border is arranged above said laminas and the region that is formed with elastic threads of reduced diameter, and therefore has a reduced thickness, is located at the passage formed between the laminas.
In order to achieve a good result in sewing, the thicker border must rest along its entire extension against the upper side of the laminas of the conveyor. This is the only way in which the sewing line or lines will affect the first rows of knitting of the actual hosiery item and the additional hosiery item portion will be removable substantially completely, achieving a scarcely visible seam.